Carburetor for internal-combustion engines



Nov. 22, 1927.

F. F. sTRArToN CARBURTOR FOR INTERNAL COMBUSTION ENGINES Filed'Nov. 4s, 1924 2 sheetsfsneet 1 ATTORNEYS Nov. 22, 1927.

F. F, STRATTON CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Nov. s, 1924 "2 Sheets-snm 2 Patented Nov. 22, 1927.

sarES PATET oFriCii,v

EENToN FREDERICK sTEATroN; or EAsii eEoYDoN, ENGLAND.

cARBURE'roR Eon iNrEaNanooiviEusfrroN ENGINES.

Application lred November 3, 1924, Serial 1\To.`747,5?,fanrl in Great Britain November '7,y 1923.

The chief object of this invention to provide a regulated and controlled means for delivering the liquid fuel vin the carburetor preferably by gravity and without the use of float feed means for maintaining a constant level. A further object of this invention is to simplify the construction of caiburetors and to reduce the parts thereof in order that the cost of production may be reduced.

ln the present invention I provide a small piston controlled nozzle arranged immedi` ately adjacent and laterally withrelation to a casing of the throttle valve `which islpreferably of the tapered `plug type,` and there maybe two, threefoi inoresuch small pis ton controlled valves to operate as main noz-` zles in addition to the pilot nozzle. f

I provide a screw down controlling `needle adapted to control the passage of liquid fuel by inea-ns of `a taperedpoint fitting loosely within a narrow orifice i. for the deliveryof fuel. This orifice opens into the air passage of the valve. f

The said tapered point `is provided withl adjustable means suoli as a suitable nut whereby the flow of liquid is accurately adjusted for a maximum and theliquid passes through a minute channel within a fixed sleeve into the pilot nozzle control chamber. l provide within `the said control chamber which is preferably arranged horizontally with relation to the carburetor a! small pis-j v l n `the liquid fuel through the piston, through( ton adapted to slidein said control chamber as a cylinder. The piston has fitted in the open end thereof a spring and the front orV head of the piston is provided with a tapered point preferably steel which is adapted to fit or seat on the aperture in theother or inner end of the sleeve or nozzle provided with the said narrow or small `orifice for the delivery of fuel. Thus the piston by means of the spring and the tapered point valve concentrically arranged on the head thereof, normally closes the fuel orifice.y

A. number of air holes are provided `in the cylinder wall so arranged that they are very nearly closed when the spring loaded piston has its taperedV valve point seated upon the fuel orifice.

Means are provided in each piston consisting preferably of a cap or an adjustable sleeve4 .for the other end of the spring to abut against, whereby the'tension of the spring upon the said seated valve may be `variedor adjusted without taking down the `carburetor or removingthe control valve thereof.

The said means may consist of a nut or nuts passing through a slot in the cylinder wall whereby the sleeve cap may be moved `in the `cylinder in order to increase orde crease the compression of the spring or a small lever with an eccentric may be provided on the exterior of the cylinder in order to vary the"tension ofthe spring` more The throttley valve in this invention suil rounds the main niixingfchamberof the carburetor, and is adapted to be given a partial `rotation within its casing, the casing having preferably cylinders.

cast therewith the nozzle 1n sta.rting,when the suction of the engine is exerted upon the Vsmall pilot nozzle piston and valve, atmospheric pressure )moves the piston against the action of the spring. and

ropensthe .fuel 'orifice while air passingm through the said air holes or passages sweeps a port provided inI the end `of the cylinder and through a corresponding small .passage brings a port in the wall of same into reg` ister with the port in the main piston valve [cylinder whereupon atmospheric pressure moves the piston valve against the action of the spi-ing and opens the main nozzle to permit the passage of fuel. If a third piston valve and second main nozzlebey fitted, this is opened by progressive further action of the throttle valve. On the opposite side of the throttle valve a control cap with aperture is provided for additional air supply. When the throttle valve is moved to the 'full register of the portV in saine withthe main nozzle port the piston valve has opened the main nozzle to the maximum.

Means 'hife provided ',suohias 2a disc fitted1 under ytl'i'"atldi'tina'l air inlet cap to control the amount of air permitted to pass."

In kthe appended'.drawingsz-v Fig. l is a sectional elevationA through the carburetor in the plane 't the pilot nozzle.

'Fig ,2 is an endview of the carburetor.L

Figf'is; a' "sectional elevation from' Vthe plane of the main nozzle.

Fig. lis"a"plan section through the pilotv,

and the mainnoz'zle.

kA'is the' main ycarburetor casing which has' the plug throttle valve B fitted therein, the` passage or cl1annel"B"fis formed laterally in'thethrttle'valve B, and this passage is' adapted to register 4for.,starting or slow running yWith'the 'channel4 A which is open Lto the cylinder 'A2, In ,the cylinder A2z is iitted thejvpistonC.'which.is vanfeasy sliding lit therein- 'The pla'te orwdilaphragm of the piston' Cxhas' 'three or more ports D therein lfort-he'passage 'ofv'air 'and the centre ofthe pisto'11'- C li'a's' 'screwed y 4'therein ythe hardened ste'e'l'point EA which point is adapted to tit.

vided 'fat the end with'` a `tapered point Hf.' fitting Within the Hchannel F3 in the Sleeve or.. nozzle. The channel F3 is contractedatiF.

and opens into, the channel, F ,at the mouth of Awhich `the valve pointrE seats. lVhen the carburetor` Ais not in operation the tapered valvepointtis kept `u'pon its Seating bythe spring K2. I is a lport or passage communicating with the outer' air, admitting air rtoA the'cyl'mderV Aznvso that when the port A coinniunicates'with the passage B and there is a vnegative pressureinsidey the carburetor, atmospheric pressure moves the V.piston C against the` pressure of the spring to lift the steelpointed valve E from itslseating in the nozzle F, permitting liquid fuel to pass through into the Acylinder. The movement of the piston IC further opens the port/or.'

ports I so 'that the; valve E is opened more widely and a greateramount of liquid fuel and larger volume of air are allowed to enterhfor starting. j This air sweeps theliquid fuel depositedidn the piston'C through the ports D bythe portrA and the passage B into the carburetor forl the engine supply, the air being limited by the area of port-s D. By furtherv movement of ,the -throttle yvalve nozzle.

by the lever N and the spindle O for acceleration, t-he passage B is brought out of register with the passage A and is closed, while the channel S leading to the main valve nozzle is partly opened by the port B2 in the throttle valve B, see Figs. Sand 4.

TheY main valve nozzle also lettered F being of the same construction and operation is contained in the second cylinder A which is integrally formed with the cylinder A and the maincarburetor casing A.

The several parts of the main nozzle having a similar construction and operation to Vthe''respective parts of the pilot nozzle `and controlling valve, have the Same lettering, rthe air ports of the main nozzle however being of a larger size.

Thepassage Hlto the main nozzle is iin- Vmediately'beneathhthe supply pipe L from the tank which is connectedby the union Lftothe cover Gr.. VA;.si1nilar. controlling taperedY needle point H. with an adjusting' nutfor the screw H is fitted in the passage F3 of the main nozzle in which there is a similar valve E of a much larger diameter, seating within the mouth or orifice of the Theport Ifin the cylinder is of a much larger area for the admission of air,

and theV ports D` in the piston C are also much larger to correspond, to permit the necessary volume of air to pass to supply air for combustion for the main nozzle.

The adjustable sleeve cap Kand the spring K2 are fitted in the cylinderA A in an adjustable manner by nuts K". By loosening the nutsthe cap maybe moved along the cylinder with regard to the nozzle Ato increase orI decrease the tension of the spring and therefore thedegree of openingqof the nozzle. lVhen therefore the port BL is opened bymeans of the'lever, N, the piston CV slides foruardlyinv the cylinder A and l progressively opens the 4air port l', at the sainel time progressively opening by means ofthe tapered valve l1. the outlet for liquid fuel in the nozzle F untilI the full supply of like liquid fuel is `permitted 'to pass through the nozzlel F for the supply of the engine.

Additional air is fled, to the. carburetor through the channel R' in the casing A which is arranged to register with the port B3, simultaneously with the registering of the port lB2 in the throttle valve with the port or channel S leading from the `main nozzle. Y

When the requisite supply of air has been determined for a certain fuel, a disc having a suitable hole or aperture is fitted within lthe eap M screwed onto thel exterior of the projecting tub'e of the channel R.

It vwill be observed that the port B will open progressively as well as siniultaneously lwith the port B2 during thefturning ot the throttle valve.

The means for adjusting 'the position of the cap K by means of the nutK are the same in the main nozzle as that described with reference to the pilot nozzle, for the purpose of varying' as desired the tension of the spring Without havingto take the carburetor to pieces.

A second or a third main nozzle may be fitted when desired topa carburetor casing such as A, by extending the length of same, and'similarly extending the length of the throttle valve B fitting Within same.

Although the construction described and shown isspecially applicable to the use of carburetors fed by gravity and having no float feed, the carburetor is adaptable and applicable if desired also to those having a float feed. ihis construction of carburetor has the particular advantage that it is applicable for use feeding at any desired angle with the engine and the inlet thereto. The fuel feed cylinders may be horizontal as shown or vertical or at anydesired angle thereto. A. Hoat feed in a carburetor necessitates-the carburetor being arranged y in practically one position only With relation to the level of the liquid in the float feed.

lWhat l do claim as my invention and desire to secure by Letters Patent is A carburetor comprising, a plurality of cylindrical mixing chambers, a liquid fuel inlet passage common to said plurality of mixing' chambers, an adjustable fuel feed nozzle projecting into each of said mixing chambers, air ports in each of said mixing chambers, a suction-operated ap-ertured piston valve slidably disposed in each of said mixing chambers, each of said piston valves controlling both the fuel feed nozzle and the air ports of itsV appropriate mixing chamber, a return spring bearing on each of said apertured piston valves, means operable externally of the carburetor to regulate the tension of each of said return springs, a throttle valve, means to oscillate said throttle valve, and ports in said throttle valve adapted to be caused to communicate in appropriate sequence with said mixing chambers. j l i 2. A carburetor comprising, a plurality of cylindrical mixing chambers and a throttle valve casing, a throttle valve in said casing, means for oscillating said throttle valve, a liquid fuel inlet passage common to said plurality of mixing chambers, an adjustable fuel feed nozzle projecting axially into .each of said mixing chambers, air ports in each yof said mixing chambers adjacent to said fuel feed nozzles, a suction-operated apertured piston valve slidably disposed in each of said mixing chambers, a member carried by each of said piston valves to co-act With one of said fuel feed nozzles, each of said piston valves controlling both the fuelv feed nozzle and the air ports of its appropriate retor toregulate the tension of each of said return springs. Y i

3. A carburetor comprising, a plurality of cylindrical mixing chambersand a throttle valveV casing, a throttle valve in said casing, means to oscillate said throttle valve', one of said cylindrical mixing chambers being of smaller capacity than the remainder, a liquid fuel inlet passage common to said plurality of mixing chambers, an adjustable fuel feed nozzle projecting from said inlet passage axially into each of said mixing chambers, air ports 1n each of said mixing chambers adjacent to said fuel feed nozzles, a suctionoperated apertured piston valve slidably disposed in each of said mixing chambers, a member borne axially by each of said pistonvalves to co-act With its appropriate fuel feed nozzle, each of said piston valves controlling simultaneously the fuel feed nozzle and the air ports of its respective mixing chamber, a mixture outlet port in each of said mixing chambers, ports in said throttle valve each adapted to register in appropriate sequence With one of said4 mixture ports, a return spring bearing on each of said apertured piston valves, and means operable externally of said carburetor to regulate the tension of each of said return springs.

4. A carburetor comprising, a pilot cylindrical mixing chamber, amain cylindrical mixing chamber, a liquid fuel inlet passage common to said pilot and said main cylindrical mixing chambers, an adjustable pilot fuel feed nozzle, an vadjustable main fuel feed nozzle, air ports in said pilot mixing chamber, air ports in said main mixing chamber, a suction-operated pilot piston valve slidably disposed in said pilot mixing chamber, a suction-operated apertured main piston valve slidably disposed in said main mixing chamber, the former of said piston valves controlling simultaneously the pilot fuel feed nozzle and its adjacent air ports and the latter of said piston valves controlling simultaneously the main fuel feed nozzle and its adjacent air ports, a mixture outlet port in each of said mixing chambers, a return spring bearing on each of said apertured piston valves, means operable externally of the Ycarburetor to regulate the tension of each of said return springs, a throttle valve, means to oscillate said throttle valve7 and pilot and main ports in said throttle valve adapted to be caused through said mixture outletportsto communicate in@ appropriate sequencey With-said pilot. and mannmixing.:chambers;YV

5. In a carburetor, :1 cylinder lhznf'i'ngzin 5"*1ts5s1de :wall at oneend an :nr inlet and ,at

10. in conicnlwalve projecting-from.the partition,. :L feed, nozzle :projecting into the cylinder, :L throttle vulve casing in'wlnch the cylinder is veccnred and an oscillating throttle valve `in said .casing nndffhavingfn yport I ll, adapted to register Auth the port ofthe sind cylinder.

mamme;

6. In a carbtmetOr, atlirottle valve casing,

annoscilla'ting'throttle valve inthe casing` ancl;hav1ng ports ot' .diercnt'^sizes, two cyl-- lnders secured to the said casmgs :1nd each f' having a portin its end, the ports beingof diferent sizes,l :1.1spring-presscd pistoni in each cylinder :ind controlling the air inlet thereof, each piston valve beingfprovided .withLzin npertured pzutitionadjacent its endy n conical valve projecting from the partition., of each piston valve, the valves beingl ot unequzrhsize, und; a :feed nozzle proJectf'.

inginto veach cylinder and into which the conical valvelof the piston valve projects.

FENTON FREDERICK?s'rnn'r'rona. 

